Free piston pumping device for gas wells and oil wells



Dec. 22, 1959 D. G. KNox 2,918,015

FREE PISTON PUMPING DEVICE FOR GAS WELLS AND OIL WELLS Filed Sept. 2,1958 6 Sheets-Sheet l .N ...GQ

QS. QN mmlwwmm 4 NN SQ. HS. .-.Iiinsub. mw q i .www Nb. 6 mv. .|I| Lm-Nnwn MN i vm SNN mm l mm. NNN mm WN Mm. F

IN V EN TOR. DO/V/Q G. ,@/VO/ 91A/ 54x p17' f @ENE YS Dec. 22, 1959 l11G. KNOX 2,918,015

FREE PISTON PUMPING DEVICE FOR GAS WELLS AND OIL WELLS Filed Sept. 2,1958 6 Sheets-Sheet 2 IN VEN TOR. DONC/ 6 KNO/V Dec. 22, 1959 FREEPIsToN PUMPING DEVICE FOR GAS WELLS AND OIL WELLS Filed sept. 2, 1958 ui; Lm@ 6 (n w y www L Y Y @M w www w, MENU gg w FREE PIsToN PUMPINGDEVICE FOR GAS wELLs AND oIL wELLs Filed sept. 2, 1958 D. G. KNOX Dec.22, 1959 6 SheeKcs-Sheet 4 H E LME.

IN VEN TOR. 00A/,1240 G. ,eA/0X T'OE/VEYS Dec. 22, 1959 D. G. KNox2,918,015

FREE PISTON PUMPING DEVICE FOR GAS WELLS AND OIL WELLS 6 Sheets-Sheet 5Filed Sept. 2, 1958 5l INVENTOR.

00A/,Q0 G. ,eA/0X 8. l BY D. G. KNox 2,918,015

FREE PIsToN PUMPING DEVICE FOR GAS WELLS AND OIL WELLS 6 Sheets-Sheet 6@E @d w m umm. JN m www.

EN bd QN NNN Dec. 22, 1959 Filed sept- 2,` 1958 auf@ A77' 70,@/1/54/5FREE PrsroNrUMPr'NG DEVICE Fon GAS WELLSY AND oIL WELLS t ApplicationvSeptember 2, 1958, Serial No. 758,21

i 1s Claims. v(cl. 10s- 52) t This invention relates to free pistonpumping devices of the general type shown in my prior Patents No.2,699,121;` 2,661,024; 2,642,002. In such devices, a plunger travels fora 'substantial distance in an eduction tube in a well under pressure ofgas below the plunger to raise a load of well iluid to the surface.Devices of this type have commonly been used for many years to raise oilto the surface and more'recently such devices have been used to removesalt water as it accumulates in gas wells, to prevent drowning of thewell.

It is the principal object of this invention to provide an improved`form of free piston pumping device which may be used to raise oil fromoil wells or to remove unwanted salt water from gas wells, and in whichthe Vvcycle of operation is controlled from the surfaceby means of atimer. Another object is to provide such a device which operatessatisfactorily when the time cycles are unusually long and when thefluid is lifted at infrequent intervals. Another object is to provide adevice of this type in which the plunger is held at the well head duringthe major portion `of the cycle when the well liuid producedincludessand in objectionable quantities.

Another object is to provide a control device for free piston pumpingapparatus employing a mechanical timer at the surface and provided withthree-way pilot'valves so that-the motorV valve in the discharge linemay be actuated when the plunger reaches the well head. vAnother objectis to provide a device of this type in which the control valve in thedischarge line may be actuated after a Alapse of a few minutes eventhough the plunger may fail to enter the well head'at the en-d of itsupward stroke. A related objectisto provide a single pilot valve foroperating the motor control valve in the discharge line, together with atimer-operated valve and a plungeroperated valve on the well-head foractuating said pilot valve. Other objects' and advantages will appearhereinafter.

United States .Patent OAn 2,918,015 Patented Dec. 22, 1959 icc Figure 9shows details of operation of the mechanical timer in diagrammatic form.

Figure 10 isa diagram showing a modified form of my invention. y

Referring to the drawings, the eduction tube generally designated 10comprises a string of tubing which extends down into the well from thewell head 11. The Well casing 12 also extends into the well and definesan annulus 13 between the casing 12 and the eduction tube 10. A sideoutlet 14 in the well head communicates with t this annulus 13 and isconnected to a shut-ofi valve 15 housing 18. The plunger generallydesignated 19 (see This application is ya continuation-impart of myprior i application, Serial No..591,144 filed June 13, 1956 nowabandoned. f Y

In the drawings: Y

Figure 1I is a diagram partly in section, showing surface controlsconstituting a preferred embodiment' of my invention.

Figure .2 is a view similar to'Figure 1 showing a modi Figure 6-is asectional elevation showing the plunger in the eduction tube."

Figure 7 is a sectional elevation partly broken away,taken,substantially`A on the line 7-k-7 as shownin Figure 5.

YFigure-,ilfisza"transverse sectional view taken substantially On thel's-Sas'showlfi'Fige 7.

Figure 6) travels in the eduction tube 10 and passes upwardly throughthe well head 11, valve 16, nipple 17 and comes to rest within thebumper housing 18. A valve assembly 20 on the plunger 19 is closedduring the upward travel of the plunger 19 within the eduction tube 10and Well iluidfcarried tothe surface by the plunger 19 passes outwardfrom the bumper housing 18 through a discharge conduit generallydesignated 21. This conduit yincludes the shut-olf valve 22, adjustableflow bean 23, piping 24, 25, control valve 26 and ilow line 27. Ifkdesired, a by-pass line 28a may be provided around the ycontrol valve 26and furnished with a shut-olf Valve 29a.

lThe lower portion of the eduction tube 10 is conventional and may besimilar to that shown in my Patent No. 2,642,002.V

As the plunger 19 enters the bumper housing 18 at the upper end ofitspath of travel, the rod 28 is received within the central opening 29 ofthe plunger 19 and mechanically contacts the valve 20 in the' plunger tomove it to open position. Gas under pressure below the plunger 19 thenpasses through the open valve and through the central passage 29 andoutward through the discharge conduit 21 as shown in Figure 5. The rod28 is mounted on a collar 30 which is provided with central 0penings31through which fluid and gas may pass. This collar 30 normally rests onthe shoulder 32 under force of the coil spring 33. This spring acts as ashock absorber when the upperl end of the plungerA 19 strikes the lowersurface of the collar 30. A guide bar 34 fixed to the collar 30 passeslooselythrough `a central opening 35 in the washer 36 at the upper endof the spring 33.

A mechanically operated trigger 37 is mounted on the bumper housing 18and this trigger is operated by contactv with the plunger 19 when thelatter enters the bumper housing 18. When the trigger 37 is contacted bythe plunger 19 it acts to open a valve assembly 38 and thereby. ventline 39 to atmosphere, thereby ,causing the control valve 26 tomove toclosed position in the manner described below. When the control valve 26closes the path of escape 'of fluid and gas through pipey 27 from theeduction tube 10 is shut off. The plunger 19 then drops by gravitydownthrough the eduction tube 10. It remains on bottom until the controlvalve 26 is opened by the timer 40, as described below. Y

The bumper housing 18 is provided witha cylindrical opening 41 whichslidably receives the plunger 19. The bumper housing 18 is also providedwith an integral lateral extension 42 which includes a transverse bore43 intersecting the opening 41. The lateral extension 42 also includes acounterbore `44 and a clearance opening 45.

Thertrigger 37 is carried on a trigger insert plug assembly generallydesignated 46. This plug assembly 46 includesf'a body 47 having aforward cylindricalgpor- Vtion"iK-having a snug fit withithe bore 43. AAsealing ring 49 on this cylindrical portion prevents leakage. A secondcylindrical portion 50 on the body 46 is slidably received within thecounterbore 44. The body 46 is held in position against pressure withinthe opening 41 by means of compression screws 51 which are threaded inthe lateral extension 42 and which engage the surface 52. These setscrews 51 hold the body shoulder 53 against abutment S4 provided on thelateral extension42.

The trigger 37 is mounted on a pivot shaft 55 carried on the forward endof the cylindrical portion 48 of the body 46. Pivotal movement of thetrigger 37 about the shaft 55 is limited by the stationary stop element56 provided on the cylindrical portion 48. A rock shaft 57 is mounted onthe body 46 and this rock shaft extends across the cavity 57a containingthe trigger 37. A follower element 58 is fixed to this shaft and has anose portion 59 which is contacted by a surface 60 on the trigger 37.The shaft 57 extends through a seal element 61 and has a lever y62 fixedto its projecting end, and positioned within the recess 63. A projection62a fixed on this lever 62 engages one end of the movable valve elementy64 on the vent valve assembly 38. The lever 62 also serves to operate apush rod 65 for actuation of a counter mechanism 66 through bell crank67. A spring 68 acts on the lever 62 to maintain the valve element 64 inclosed position. The body 46 is prevented from turning in thecounterbore 44 by means of a set screw 69 which engages a key way 70.

When the plunger 19 engages the trigger 37 it causes the lever 62 to beswung in a counterclockwise direction as viewed in Figure 7 therebyallowing the movable valve element 64 to move to the right under theforce of gas pressure in the line 39. This action serves to bleed theline 39 to atmosphere through the lateral port 71 and through clearancespaces communicating wtih the cavity 72. The cavity 72 is not sealedwith respect to the atmosphere but communicates therewith throughclearance openings in the window 73. When the plunger 19 drops out ofthe bumper housing 18 after the control valve 26 closes, the spring 68returns the lever y62 to its initial position, thereby causing theextension 62a to Contact the movable valve element 64 and thereby closesthe vent valve assembly 38.

The line 39 is connected by T fitting 74 to line 75 leading to the pilotvalve assembly 76. The line 77 connects the non-adjustable pilot valveassembly 76 with the adjustable pilot valve assembly 78. The pilot valveassembly 76 includes a ported housing 79 having a central bore 80 whichreceives a sliding valve element 81. A spring 82 at one end of theelement 81 tends to move the other end into Contact with the cross pin83 which acts as a stop. vWhen pressure from line 75 moves the elementy81 in a direction to compress the spring 82, line 77 is vented toatmosphere through vent port 83a. When the line 75 is vented, the springmovesthe element 81 downward to contact the stop pin 83, therebyconnecting line 77 with line 84. Line 84 is connected through tubefitting 85 to pipe 86. A fitting having a small diameter orifice 87 ispositioned between pipe 86 andT fitting 74.

The pilot valve assembly 78 is provided with a housing 88 having acentral bore 89. A movable valve element 9.0 isl slidably mounted withinthe bore 89. A

against a stationary stop pin 92 at the other end. In the position shownin Figure 3, the line 93 is placed in communication with the line 94.When the valve element 90 moves upward under the application of pressureat the lower end thereof, the line 93 is Vented through the vent port95. Pressure reaches the chamber 96 at the lower end of the ybore 89 vialine 97 and groove 98 formed in the `valve element 90. A bracket 99 isfixed to one end of the housing 88 and provides a support for theadjustable member l'100. This member carries a bellows element 161 whichsupports a mov-V able valve element 102 adapted to close against astamined time intervals.

tionary seat 103. When pressure is applied from line 77, the diaphragm101 causes the valve element 102 to close against the seat 103. Whenpressure in line 77 is relaxed, the diaphragm 101 returns to its normalfree position thereby separating the valve parts 103 and 102 to bleedthe lower chamber 96 to atmosphere through the passage 104. The nut 105permits the member 100 to be fixed in axially adjusted position.

A How bean 106 receives gas under pressure from nipple 107 and this gaspasses through piping 108 and valve 109 to the sales line 110. The salesline 110 together with parts which connect it to the interior of thecasing 12 constitutes a gas line through which gas constantly flows,under normal conditions, regardless of the position of the control valve26. A supply line 111 carries gas from the ow bean 106 through shut-offcock 112 and delivers it to the filter 113. Gas from the lter passesthrough piping 114 and through the reducing regulators 115 and 116. Thegas delivered to the T fitting 117 is regulated to a predeterminedoperating pressure, for example 20 p.s.i. The T fitting 117 is connectedto the T fitting 85 and is also connected to the timer inlet at 118. Thetimer outlet 119 is connected to the T itting 120 and the latter isconnected to the lines 94 and 97.

The control valve 26 is normally closed by means of a spring. When line93 is pressurized, a diaphragm within the diaphragm chamber 121 movesthe valve stem 122 downward to open the motor valve 26. Conversely,venting of the line 93 relaxes pressure within the diaphragm chamber 121and permits the spring to close the valve 26.

The timer mechanism generally designated 40 serves to connect the inlet118 to the outlet 119 at predeter- Any suitable or desirable form oftimer may be used. In the particular form of timer illustrated in Figure9, a clock driven disk 125 is provided with detachable clips 126 whichmay be secured to its periphery. When the point of the trigger 127 fallsinto the slot left by the displaced clip,'the other end of the triggerexerts a force on the leaf spring 128. This in turn allows a primarythree-way valve 129 to open the supply port 130. The supply of gas thenflows from the inlet 118 through the valve 129, loading the diaphragm131 of the secondary three-way valve 132. Force exerted on thisdiaphragm closes this exhaust valve 133 and opens the supply valve 134to supply pressure to the outlet 119. As the timing disk turnscounter-clockwise, the timing clip engages trigger 127 forcing thetrigger to relieve its pressure on the lea-f spring 128. This allows thethree-way valve 129 to close the supply port and to open the exhaustport 135, bleeding pressure off chamber above the diaphragm 131. The gasthen closes supply valve 134 and opens the exhaust valve 133. Thepressure in the main diaphragm then bleeds out eX- haust port 136.

The pilot bleeds gas only when the primary three-way valve 129 is movingthrough the intermediate position. Secondary three-way valve 132 actsquickly and allows only a small amount of supply gas to be lost on theexhaust stroke of control valve 26. This pressure reduces thepossibility of regulator freeze-ups by avoiding any steady ovv of supplygas, and also reduces the total amount of gas used for operation;

In the operation of the form of the invention shown in Figure l, theplunger 19 stays at the bottom of the well with gas flowing from thecasing 12 through bean 106 to the sales line 110i. At the end of adesired time interval, the control valve 26 is opened, causing a rush ofgas through the ow bean 23 and through piping 24 and 25 to the tiow line27. This brings the plunger 19 to the surface, raising a fluid loadabove it. Fluid discharges through tiow bean 23 and through controlvalve 26 to the ow line 27. This ow line 27 ordinarily is connected to agas separator or sump (not shown).

After the -ud is discharged, the plunger 29 enters the entspre bumperhousing 1'8 and engages the trigger 37. This action serves to close thecontrol valve 26 in the manner described below and the plunger 29thereupon returns to the lower end of eduction tube until the beginningof the next time cycle.

The corresponding operation of the control mechanism for causing theplunger to cycle in the manner described is set forth as follows:operating pressure, for example, 20 p.s.i. in line 86 passes throughorice 87 to pressurize the trigger line 39. This pressure in line 75raises the plunger 81 of the pilot valve 7.6 Venting line 77 toatmosphere through port 83a and closing ot line 84. When the timer 40operates to press-urize the outlet 119 from the inlet 118 by-pass line97 isA pressurized. The valve element 90v in the pilot valve 78 is inthe position shown in Figure 3. This pressurizes the diaphragm chamber121 and moves the valve stem i122 downwardly to open the control valve26.

When the plunger 29 reaches the surface, it actuates the trigger 37 andthereby permits the valve'assembly 38 to vent the line 39 to atmospherethrough the Vent port` 71. The reduction in pressure in line 3-9 causesthe valve element 81 in the pilot valve 76 to movegdownward under forceof the spring `82 toconnect the pressure line 84 with the line 77. Thisin turn pressurizes the diaphragm 10'1 of the pilot valve 78 causing thevalve port v102 to close againstv the seat 103. The valve element 90 israised by pressure in the chamber 96 supplied via line 97 and groove98.V A pressure line 94 is sh-ut oi and line 93 is vented through port95. Venting of the line 93 results in upward movement of the valve stem122 to close the control valve 26.

When the control valve 26 closes, the plunger 19 drops away from thewell head thereby closing the trigger valve assembly 38, and permittingpressure in line 39 to build up 'by gas supplied through oriice 87.Pressure in the line 75 then raises the valve element 81 in the pilotvalve 76 to close ot pressure line 84 and to vent the line 77 throughthe vent port 83a. Line 93 remains vented through por-t 95 and thecontrol valve 26 remains closed. The timer 40 trips again and shuts offthe supply of gas to the outlet 119. This action releases pressure inthe bypass line 97, thus permitting the spring 91 to move the valveelement 90 in the pilot valve 78 thereby connecting line 94 with line93. The cycle is then ready to repeat.

Should the plunger 19 fail to enter the bumper housing 18, the controlvalve 26 is closed by the timer 40 shortly after the plunger 19 isscheduled to 4arrive at the well head. This is accomplished by settingof the timer mechanism. This feature avoids the possibility of loss ofgas through the line 27 in the event the plungerl should fail to reachthe upper end of its stroke within the bumper housing 18.y

Invthe modified form of my invention shown in Figure 2, the eductiontube 10, well head 1.1, casing 12valve 16, nipple 17 and bumper housing18 are substantially the used. 'Ihe bumper housing 18 and its associatedmechanism including the vent valve 38 is substantially the same aspreviously described. The mechanisni opener rod 28 is provided with anenlargementy 130a which restricts the iiow passage area within theopening29 of the plunger 19 when the latter is positioned withinY thebumper housing 18. This restriction/produces `a ,pressure drop from thebottomto the top of the plunger 19 with the result that the plunger may.be maintained within-the bumper housing until the intensity of pressureis subystantially reduced in the eduction tube below the plunger. 'Theresult is that the plunger is lheld withinV the bumper housing for asubstantial period of time before dropping back down the eductiontubev10. This form of my in- 'vention is used when sanding lor otherconditions are present which would interfere with the operation of theplunger if it were maintained on bottom for substantial Iperiods oftime.

yfrom the control valve connects to a sump (not shown). A normally opencontrol valve 138 is connected to the sales line 139 through the checkvalve 1140. The sales line 139 together with the parts which connect itto the interior of the bumper housing 18 constitutes a gas line throughwhich gasl may ow from the well regardless of the position of thecontrol valve 135. Spring loaded check valve 140 serves to prevent anyreverse flow from sales line through valve 138 when valve 135 is open tothe sump. Gas passes from the casing 12 through nipple 1/4, valve 15 andsupply line 141 to the strainer 142, and to the reducing regulator 1143.Gas from the vregulator passes through line 144 to the T fitting 145 andthence to the pilot valves 146 and 147 and to the timer 148. The pilotvalves 146 and 1147 are substantially duplicates and are the same aspilot valve 76 shown in Figure 4. Timer mechanism 148 is substantiallythe same as timer 40 previously described. The line 149 connects withthe pilot valve 146 and with the diaphragm chamber 150 of the controlValve 135 via branch pipe 151. Line 152 connects the pilot valve 146with the timer 148 and the line 153 connects the timer 148 with thepilot valve 146 Via T tting 154, and with pilot valve 147 via branchpipe 155. The line 156 connects the pilot valve 147 with the diaphragmchamber 157 of the normally open control valve 138.

In the operation of this form of my invention, the plunger 19 remains inthe bumper housing 18 while gas passes outward through ow bean 23 andthrough normally open valve 138 to the sales line 139. Plunger 19 incontact wit-h trigger 37 releases pressure in line 1i49. Pilot valve 146connects line 1'49 with the pressure line 152 and pilot valve 147 ventsline 156 through vent port 158. Control valve 1.35 remains closedbecause pressure in the branch pipe 151 is released through pilot valve38. This is because port in pilot valve 38 is larger than restrictingorice 160.

When the timer 148 trips to interrupt the supply of gas to the line 153,the pilot valve 147 connects line 144 to line 156, pressurizing thediaphragm chamber v157 and thereby closing the valve 138. Thus motorvalve 135 remains closed permitting plunger to descend.

When the timer 148 again trips to pressurize line 153, pilot valve 147connects line 156 to the vent port 158 thereby opening Valve 138. Pilotvalve 146 connects line 152 through orice 160 to line 149 therebycausing valve 135 to open slowly to sump as pressure builds up inpressure line 149. The plunger 19 begins to rise in the ednction tube10. When the plunger 19 strikes the trigger 37 the vent valve 38 opensto bleed the line 149. The valve 135 closes gradually as the pressure inthe diaphragm chamber is bled to atmosphere. The plunger 19 remains inthe bumper housing 18 because of the restrictiony imposed by theenlargement 130a. The cycle is then ready -to repeat.

Although I have described certain embodiments of my invention nconnection with removal of unwanted salt water from gas wells, myinvention is notlimited to such use but can be applied to advantage forthe production of oil from oil wells.

In the modied form of my invention shown in Figure l0, the eduction tube10, well head 11, casing 12, valve 16 and nipple 17 are substantiallythe same as described in connection with Figurel. The same plunger 19 isused and the bumper housing 18a is similar to the bumper housing 18 butis constructed of non-magnetic material, for example l8-8 austeniticstainless steel. 'Ilhe vent valve assembly 38a replaces the vent valve38 and a magnetically operated trigger device 210 replaces themechanical trigger 37. This device 210 includes a permanent magnet 211mounted on a pivoted arm A212 and adapted to swing in a counterclockwisedirection, as

viewed in Figure 10, whenever the plunger 19 enters the bumper housing18. The construction and operation ofthis magnetic trip device 210 iscontained in the copending application of William A. Shaw, Serial No.640,365, filed February l5, 1957.' A spring 213 normally holds'the arm212 in its retracted position and contact between the arm and slidingvalve element 214 holds the latter in closed position against the seat215. Line 216 communicates with the seat and with line 119 extendingfrom the timer operated valve.

A chamber 217 vencloses a portionv of the moving valve element 214Y andis connected by means of a line 218 to the diaphragm chamber 219 in thepilot valve assembly 220. A valve spool 221 is lixed at one end to thediaphragm 222 and the other end is open to atmosphere. A spring 223 acts-to move the spool 221 in the direction toreduce the volume ofthediaphragm chamber 219. A port 224 in the housing 225 connects with thegas line 119 from the timer valve. The control valve 26 in the dischargeline is-substantially Ithe same as that described. in connection withFigure 1, and the diaphragm chamber 226 thereof is connected c by line227 to theport 228 in the housing 225 of pilot valve assembly 220. v

Gas under pressure delivered to line 119 from the timer valvespressurizes 'line 216 leading to the trigger valve assembly 38a, andalso pressurizes line 227 through open port in valve 220 leading to thediaphragm chamber of the control valve 26 in the discharge line 27. Theplunger valves 129 and 132 open when the clock driven timer wheel 125reaches a predetermined position, as described above. The plunger 19 isat the bottom of the ywell at that time. Opening of the controlvalve 26in the discharge line 27 reduces the pressure 'within the eduction tube16, and the plunger 19 begins its upward trip, carrying a load of Welluid above it. When the plunger 19 enters lthe interior of the bumperhousing 18, the magnetic attraction between the magnet 211 and the metalof the plunger causes the pivoted arm 212 to swing in a counterclockwisedirection against the action of the spring 213. The moving valve element214 then moves away from the seat 215 to allow gas in the line 216 topressurize the chamber 217 and deliver gas underl pressure through line218- to the diaphragm chamber 219 of the pilot valve assembly 220. Thediaphragm 222 moves downward against the action of the spring 223 tomove the spool 221 and change' the porting. This serves to vent the line227 to atmosphere and allow the internal spring 229 in the control valve26 to raise the valve stem and close the valve, thereby shutting in thewell. The parts are then in the position shown in Figure l0.

The plunger 19 then Vdrops back down the eduction tube 10, and thepivoted arm 212 is swung in a clockwise direction by ythe spring 213,and this serves to move the valve element 214 into closed positionagainst the seat 215.

It should be noted that the timer clock continues to drive the Itimerwheel 125 `and if, through some circumstance, the plunger 19 fails toarrive at the surface and enter the bumper housing 18, the timer wheel125 will act after a predetermined interval to close the valve 129 andthereby close the valve 132. Closing of the valves 129 and 132 shuts olfthe supply of gas to the diaphragm chamber 226, at the same time ventingport 136 to atmosphere, permitting the spring 229 to close the controlvalve 26 in the discharge line 27. Thus, the lwell is shut in after apredetermined time interval even though the plunger 19 should fail toarrive at the surface.

Closing of the timer valves 129 and 132 in the normal sequence ofoperation occurs after the plunger 19 has dropped downward out of thebumper housing 18 and after the valve element 214 is closed against theseat 215. Gas in lines 119 and 216 is vented to atmosphere through thevent port 136 (see Figure 9) and gas in the 8 lines 218, 231 ventsthrough a restriction 232 into the space 234 within the valve housing225. The space 233 communicates through line 119 with atmospheric ventport 136 so long as -the valve spool 221 is in this position. Whenescape of gas from the chamber 219 permits the spring 223 to raise thediaphragm 222, the line 231 is vented through restriction 232 toatmosphere through the ported 'chamber 234. The parts are then in theinitial position and the cycle repeats as soon as the timer plate 125moves to bring the next gap in the clips 126 into position opposite thepoint of the trigger 127.

Having fully described my invention, it is to be understood that I donot wish to be limited to the details herein set forth, but my inventionis of the full scope of the appended claims.

I claim:

l. In a gas well installation having an eduction tube connected to awell head, the improvement comprising, in combination: a valve plungeradapted to travel freely under pressure substantially the full length ofthe eductiontube to remove accumulations of liquid in the well, adischarge conduit connected to the well head, a first `control valveoperatively connected to the discharge conduit, a second control valveoperatively connected to the discharge conduit, a movable triggerelement positioned adjacent the well head and adapted to be mechanicallyactuated by physical contact with said plunger, means for closing thefirst said control valve upon actuation of said trigger, a timer deviceoperatively connected to close the second control valve at predeterminedtime intervals.

2. In a gas well installation having an eduction tube connected to awell head, the improvement comprising, in combination: a valved plungeradapted to travel freely under pressure substantially the full length ofthe eduction tube to remove accumulations of liquid in the well, adischarge conduit connected to the well head, a first control valveoperatively connected to the discharge conduit, a movable triggerelementpositioned adjacent the well head and adapted to be mechanicallyactuated by physical contact with said plunger, means for closing the-rst said control valve upon actuation of said trigger, a second controlvalve operatively connected to the discharge conduit, gas actuated meansincluding a pilot valve for closing the second control valve, and atimer device operatively connected to supply a gas under pressure tosaid pilot valve at predetermined time intervals.

3. In a gas well installation having an eduction tube connected to awellv head, the improvement comprising, in combination: a valved plungeradapted to travel freely under pressure -substantially the full lengthof the eduction tube to remove accumulations of liquid in the well, adischarge conduit connected to the well head, a iirst control valveoperatively connected to the discharge conduit, avmovable triggerelement positioned adjacent the well head and adapted to be mechanicallyactuated by physical contact with said plunger, pneumatic means'forclosing the iirst said control valve upon actuation of said trigger, asecond control valve operatively connected to the discharge conduit,pneumatic means for closing 'the second control valve at predeterminedtime intervals, and means adjacent the well head for maintaining theplunger vat the upper end of its stroke so long as either of saidcontrol valves is open.

4.7In a device for use with a valved plunger adapted to travel freelyunder pressure substantially the full length of anv eduction tubeinatwell, the combination of: a bumper housing having a longitudinalopening to receive the plunger, the bumper housing having an integrallateral extension provided with a bore intersecting said longitudinalopening, a body removably secured within the bore andhaving a movabletrigger mounted thereon for contact with the plunger, the body having arecess, seal `means preventing leakage between said longitudinal boreand said recess, and a vent valve assembly isad recess adapted to beactuated by the trigger. I

5. In a device kfor use with a valved plunger adapted to travel freelyunder pressure substantially the full length of an eduction tube in yawell, the combination of: a bumper housing having a longitudinal openingto receive the plunger, the bumper housing having an integral lateralextension provided with a bore intersecting said longi- -tudinalopening, a shoulder insaid bore, a body removably mounted within thebore in sealing relationship, at least one threaded element on thebumper housing extension engaging the body to maintain the'body incontact with said shoulder, a movable trigger mounted on the body forcontact with the plunger, and a vent valve assembly on the body adaptedto be actuated by the trigger.

6. In a device for use with a valved plunger adapted to travel freelyunder pressure substantially the full length of an eduction tube in awell, the combination of: a lbumper housing having a longitudinalopening to receive the plunger, the bumper housing having an integrallateral extension provided with a bore intersecting said longitudinalopening, a shoulder in said bore, a body removably mounted within thebore in sealing relationship, at least one threaded element on thebumper housing extension engaging the body to maintain the body in con--tact with said shoulder, a movable trigger for contact with the plungerand a counter to be actuated by the trigger.

f 7. In a well pump device having a plunger adapted to travel in aneduction tube to deliver well fluid into a discharge line, the dischargeline being connected to a well head at the upper end of the eductiontube, and a pressure operated control valve in the discharge line, theimprovement comprising in combination: a timer device, a fluid pressuresupply conduit, means including valve means in said fluid pressuresupply conduit operated by the timer device for opening the controlvalve and subsequently closing it after a predetermined time interval,and means including a valve assembly on the well head acting to closethe control valve in response to entry of the plunger into the well headduring said time interval.

8. In a well pump device having a plunger adapted to travel in aneduction tube to deliver well fluid into a discharge line, thedischargetline being connected to a Well head at the upper end of theeduction tube, and a pressure operated control valve in the dischargeline, the improvement comprising in combination: a timer device, a fluidpressure supply conduit, a pilot valve connected to operate the controlvalve, valve means in said fluid pressure supply conduit operated by thetimer device for delivering Igas under pressure to the pilot valve andsubsequently closing olf such delivery after a predetermined timeinterval, and means including a valve assembly on the well headconnected to the pilot valve and acting to close the control valve inresponse to entry of the plunger into the Well head during said timeinterval.

9. In a well pump device having a plunger adapted to travel in aneduction tube to deliver well Huid into a discharge line, the dischargeline being connected to a well head at the upper end of the eductiontube, and a pressure operated control valve in the discharge line, theimprovement comprising in combination: a fluid pressure supply conduit,means including valve means in the fluid pressure supply conduit foroperating the control valve, timer means controlling the operation ofsaid valve means whereby the control valve is opened and thensubsequently closed after a predetermined time interval, and meansincluding a valve assembly on the well head acting to close the controlvalve in response to entry of the plunger into the well head during saidtime interval.

l0. In a free piston well pump device having an eduction tube connectedto a well head, a plunger adapted to travel freely under pressure withinthe eduction tube vi0 y to remove accumulations of liquid in the well, adischargd conduit connected to the well head and communicating with thetubing to carry away said liquid, and a pressure operated control valvein said discharge conduit, the improvement comprising, in combination: apilot valve assembly connected to operate the control valve, a timermechanism, a pressure lluid conduit connected to the pilot valveassembly, valve means operated by the timer' mechanism for deliveringlluid under pressure to the pilot; valve assembly to cause opening ofthe control valve, said timer mechanism also acting to shut olf thesupply ofV gas after a predetermined time interval and thereby closesaid control valve and means including a valve assembly on the well headacting on the pilot valve to` close the control valve in response toentry of the plunger into the well head during said time interval.

ll. In a free piston well pump device having an eduction tube connectedto a well head, a plunger adapted' to travel freely under pressurewithin the eduction tube to remove accumulations of liquid in the well,a dischargev conduit connected to the Well head and communicating withthe tubing to carry away said liquid, and a pressure operated controlvalve in said discharge conduit, the improvement comprising, incombination: a pilot valve assembly connected to operate the controlvalve, a timer mechanism, a pressure fluid conduit connected to thepilot valve assembly, valve means operated by the timer mechanism fordelivering iluid under pressure to the pilot valve assembly to causeopening of the control valve and means including a valve assembly on thewell head connected to the pilot valve and acting to close the controlvalve in response to entry of the plunger into the well head, said timermechanism also acting to clo-se said valve means after a predeterminedtime interval in the event that the plunger should fail to enter thewell head. 12. In a well installation having an eduction tube connectedto a well head, an improvement comprising, in combination: a plungeradapted to travel freely under pressure substantially the full length ofthe eduction tube to remove accumulations of liquid within the well, adischarge conduit connected to the well head, a first control valveoperatively connected to the discharge conduit, a second control valveoperatively connected to the dis charge conduit, a movable elementpositioned adjacent the well head, means for moving said element inresponse to entry of the plunger into the well head, means for closingthe first said control valve upon movement of said movable element, anda timer device operatively connected to close the second control valveat predetermined timeintervals.

13. In a Well installation having an eduction tube connected to a wellhead, an improvement comprising, in combination: a plunger adapted totravel freely under pressure substantially the full length of theeduction tube to remove accumulations of liquid in the well, a dischargeconduit connected to the well head, a first Acontrol valve operativelyconnected to the discharge conduit, a movable element positionedadjacent the well head, means for moving said element in response toentry of the plunger into the well head, means for closing the rst saidcontrol valve upon movement of said movable element, a second controlvalve operatively connected to discharge conduit, means including apilot valve for closing the second control valve, and a timer deviceoperatively connected to supply fluid under pressure to said pilot valveat predetermined time intervals.

14. In a well pump device having a plunger adapted to travel in aneduction tube to deliver well Huid into a, discharge line, the dischargeline being connected toa well head at the upper end of the eductiontube, and a pressure operated control valve in the discharge line, theimprovement comprising, in combination: a timer device, a liuid pressuresupply conduit, means includingvalve means in said fluid pressure supplyconduit oper-` ated by the timer device for opening the control valve;

and subsequently closing it after a predetermined time interval,meansincluding a valve assembly on the wellhead operable lto close thecontrol valve, the valve assembly including a movable valve element, andmagnetic means on the Well head operable to actuate said valve elementin response to entry of the plunger into the well head during the saidtime interval.

15. In a well pump device having a plunger adapted to travel in aneduction tube to deliver Well fluid into a discharge line, the dischargeline being connected to a Well head at the upper end of the eductiontube, and a pressure operated control valve in the discharge line, theimprovement comprising in combination: a timer device, a tluid pressuresupply conduit, a pilot valve connected to operate the control valve,valve means in said fluid pressure supply conduit operated by the timerdevice for delivering gas under pressure to the pilot valve andsubsequently closing 01T such delivery after a predetermined timeinterval, means including a valve assembly on the 'well head connectedto the pilot valve and operable to =close the control valve, the valveassembly including a movable valve element, and magnetic means on theValve head adapted to actuate the valve element in response to entry ofthe plunger into the well head during said time interval.

16. In a well pump device having a plunger adapted to travel in aneduction tube to deliver well fluid into a discharge line, the dischargeline being connected to a well head at the upper end of the eductiontube, and a pressure operated control valve in the discharge line, theimprovement comprising in combination: a lluid pressure supply conduit,means including valve means in the lluid pressure supply conduit foroperating the control valve, timer means controlling the operation ofsaid valve means whereby the control valve is opened and thensubsequently closed after a predetermined time interval, means includinga valve assembly on the well head operable to close the control valve,the valve assembly including a movable valve element, and magnetic meanson the well head adapted to actuate the valve assembly in response toentry of the plunger into the well head during said time interval.

17. In a free piston well pump device having an eduction tube connectedto a well head, a plunger adapted to travel freely under pressure withinthe eduction tube to remove accumulations of liquid in the well, adischarge conduit connected to the well head and communicating rwith thetubing to Cary away said liquid, and a pressure operated control valvein said discharge conduit, the improvement comprising, in combination.:a pilot valve as,- sembly connected to operate the control valve, atimer mechanism, a pressure duid conduit connected to the pilot Valve`assembly, valve means operated by the timer mechanism for deliveringfluid under pressure to the pilot valve assembly to cause opening of thecontrol Valve, said timer mechanism also acting to shut off the supplyof gas after a predetermined time interval and thereby close saidcontrol valve, the valve assembly including a movable valve element, andmagnetic means on the well head adapted to actuate'the valve element inresponse to entry of the plunger into the well head during said timeinterval.

18. In a free piston well pump device having lan eduction tube connectedto a well head, a plunger adapted to travel freely under pressure`within the eduction tube to remove accumulations of liquid in the well,a discharge conduit connected to the well head and communicating withthe tubing to carry away said'liquid, and a pressure operated controlvalve in said `discharge conduit, the improvement comprising, incombination: a pilot valve assembly connected to operate the controlvalve, a timer mechanism, a pressure fluid conduit connected to thepilot Valve assembly, valve means operated by the timer mechanism vfordelivering fluid under pressure to the pilot valve assembly to causeopening of the control valve, means including a valve assembly on thewell head connected to they pilot valve and operable to close thecontrol valve, the valve assembly-including a movable valve element, andmagnetic means on the well head adapted to actuate said valve element inresponse to entry of the plunger into the well head during said timeinterval.

References Cited in the tile of this patent UNETHED STATES PATENTS2,001,552 Scott M ay 14, 1935 2,642,002 Knox et al. June 16, 19532,649,738 Tait Aug. 25, 1953 2,661,024 Knox Dec. 1, 1953 2,699,121 KnoxIan. 11, 1955 2,714,855 Brown Aug. 9, 1955 2,762,309 Knox Sept. 1l, 1956

